Azalea plant named &#39;RLH1-15P3&#39;

ABSTRACT

A new and distinct cultivar of Azalea plant named ‘RLH1-15P3’, characterized by its compact, upright to outwardly spreading and rounded plant habit; freely basal branching habit; dense and bushy appearance; vigorous growth habit and rapid growth rate; evergreen, persistent dark green-colored leaves that do not abscise during the winter; freely flowering habit with remontant flowering during the spring, summer and autumn; large, non-persistent single flowers that are white in color greenish white-colored central spots and speckles; and excellent garden performance and temperature tolerance.

BOTANICAL DESIGNATION

Rhododendron hybrida

CULTIVAR DENOMINATION

‘RLH1-15P3’

BACKGROUND OF THE INVENTION

The present Invention relates to a new and distinct cultivar of Azaleaplant, botanically known as Rhododendron hybrida, commercially referredto as an evergreen Azalea plant and hereinafter referred to by the name‘RLH1-15P3’.

The new Azalea plant is a product of a planned breeding programconducted by the Inventors in Long Creek, Oconee County, S.C.. Theobjective of the breeding program is to create new compact evergreenAzalea plants having dense growth habit, large attractive flowers,flowers with good temperature tolerance, consistent remontant floweringduring the spring, summer and autumn, good garden performance and lowand high temperature tolerance.

The new Azalea plant originated from a cross-pollination made by theInventors in 1996 in Long Creek, Oconee County, S.C., of a proprietaryselection of Rhododendron hybrida identified as code number RLH-1800-WS,not patented, as the female, or seed, parent with Rhododendron hybrida‘September Song’, not patented, as the male, or pollen, parent. The newAzalea plant was discovered and selected by the Inventors as a singleflowering plant within the progeny of the stated cross-pollination in acontrolled greenhouse environment in Long Creek, Oconee County, S.C. in2000.

Asexual reproduction of the new Azalea plant by semi-hardwood stemcuttings taken in a controlled greenhouse environment in Long Creek,Oconee County, S.C. since 2005 has shown that the unique features ofthis new Azalea plant are stable and reproduced true to type insuccessive generations.

SUMMARY OF THE INVENTION

Plants of the new Azalea have not been observed under all possibleenvironmental conditions and cultural practices. The phenotype may varysomewhat with variations in environmental conditions such astemperature, daylength and light intensity without, however, anyvariance in genotype. The following traits have been repeatedly observedand are determined to be the unique characteristics of ‘RLH1-15P3’.These characteristics in combination distinguish ‘RLH1-15P3’ as a newand distinct Azalea plant:

-   -   1. Compact, upright to outwardly spreading and rounded plant        habit.    -   2. Freely basal branching habit; dense and bushy appearance;        vigorous growth habit and rapid growth rate.    -   3. Evergreen, persistent dark green-colored leaves that do not        abscise during the winter.    -   4. Freely flowering habit with remontant flowering during the        spring, summer and autumn.    -   5. Large, non-persistent single flowers that are white in color        greenish white-colored central spots and speckles.    -   6. Excellent garden performance and temperature tolerance.

Plants of the new Azalea differ primarily from plants of the femaleparent selection in the following characteristics:

1. Plants of the new Azalea are more spreading than plants of the femaleparent selection.

2. Plants of the new Azalea and the female parent selection differ inflower color as plants of the female parent selection have salmonpink-colored flowers.

Plants of the new Azalea differ primarily from plants of the maleparent, ‘September Song’, in the following characteristics:

1. Plants of the new Azalea are more spreading than plants of ‘SeptemberSong’.

2. Plants of the new Azalea are more freely branching than plants of‘September Song’.

3. Plants of the new Azalea have larger flowers than plants of‘September Song’.

4. Plants of the new Azalea and ‘September Song’ differ in flower coloras plants of ‘September Song’ have red-colored flowers.

Plants of the new Azalea can be compared to the plants of ‘Robleg’,disclosed in U.S. Plant Pat. No. 15,227. In side-by-side comparisonsconducted in Long Creek, Oconee County, S.C., plants of the new Azaleadiffered primarily from plants of ‘Robleg’ in the followingcharacteristics:

1. Plants of the new Azalea were more uniform in plant shape andrequired less pruning than plants of ‘Robleg’.

2. Plants of the new Azalea were more freely flowering than plants of‘Robleg’.

3. Flower petals of plants of the new Azalea were more ruffled andundulate than flower petals of plants of ‘Robleg’.

4. Plants of the new Azalea and ‘Robleg’ differed slightly in flowercolor.

5. Plants of the new Azalea flowered during the spring, summer andautumn whereas plants of ‘Robleg’ only flowered during the spring andautumn.

6. Plants of the new Azalea were more cold hardy than plants of‘Robleg’.

BRIEF DESCRIPTION OF THE PHOTOGRAPH

The accompanying colored photograph illustrates the overall appearanceof the new Azalea plant showing the colors as true as it is reasonablypossible to obtain in colored reproductions of this type. Colors in thephotograph may differ slightly from the color values cited in thedetailed botanical description which accurately describe the colors ofthe new Azalea plant. Plants used for the photograph were grown duringthe late summer in ground beds in a shady outdoor nursery in Long Creek,Oconee County, S.C. and under cultural practices which approximatecommercial Azalea production. During the production of the plants, daytemperatures ranged from 0° C. to 45° C. and night temperatures rangedfrom −17° C. to 38° C. Plants were seven years old when the photographwere taken. The photograph comprises a top perspective view of typicalflowering plants of ‘RLH1-15P3’.

DETAILED BOTANICAL DESCRIPTION

The following observations and measurements describe plants grown duringthe late summer in three-gallon containers in a shadehouse in El Campo,Tex. and under cultural practices which approximate commercial Azaleaproduction. During the production ofthe plants, day temperaturesaveraged 24° C. and night temperatures averaged 14° C. Plants were oneyear old when the detailed description was taken. In the followingdescription, color references are made to The Royal HorticulturalSociety Colour Chart, 2007 Edition, except where general terms ofordinary dictionary significance are used.

-   Botanical classification: Rhododendron hybrida ‘RLH1-15P3’.-   Commercial classification: Evergreen Azalea.-   Parentage:    -   -   Female, or seed, parent.—Proprietary selection of            Rhododendron hybrida identified as code number RLH-1800-WS,            not patented.        -   Male, or pollen, parent.—Rhododendron hybrida ‘September            Song’, not patented.-   Propagation:    -   -   Type.—By semi-hardwood stem cuttings.        -   Time to initiate roots, summer.—About 25 to 30 days at            temperatures of 27° C. to 30° C.        -   Time to initiate roots, winter.—About 35 to 45 days at            temperatures of 16° C. to 17° C.        -   Time to produce a rooted young plant, summer.—About 60 to 70            days at temperatures of 27° C. to 30° C.        -   Time to produce a rooted young plant, winter.—About 80 to            100 days at temperatures of 16° C. to 17° C.        -   Root description.—Fine, fibrous; initially white in color            becoming light brown with development.        -   Rooting habit.—Freely branching; dense.-   Plant description:    -   -   Plant form, plant and growth habit.—Perennial and evergreen            flowering subshrub; compact, upright to outwardly spreading            and rounded plant habit; vigorous growth habit; rapid growth            rate; freely flowering habit with numerous single flowers.        -   Branching habit.—Freely branching habit with about four to            six basal branches developing on one year old plants; dense            and bushy appearance; pinching (removal of terminal apex)            enhances lateral branch development.        -   Plant height, soil level to top of flowers.—About 35 cm to            50 cm.        -   Plant diameter, area of spread.—About 30 cm to 40 cm.        -   Lateral branch description.—Length: About 5 cm to 20 cm.            Diameter at base: About 2 mm to 5 mm. Diameter at apex:            About Internode length: About 3 mm to 19 mm. Strength:            Strong. Aspect: Upright and outwardly positioned. Texture,            developing: Pubescent, fine greyed orange-colored hairs.            Texture, mature: Woody; pubescent, fine greyed            orange-colored hairs. Color, developing: Close to 145B.            Color, semi-hardwood: Close to 145A becoming close to 165A            to 165B with development. Color, mature: Close to 165A.        -   Leaf description.—Arrangement: Alternate; simple. Leaf            retention: Very good winter leaf retention has been observed            on plants of the new Azalea. Length: About 3 cm to 6.5 cm.            Width: About 1 cm to 2.5 cm. Shape: Oblanceolate to            elliptic. Apex: Subacute; mucronulate. Base: Cuneate to            attenuate. Margin: Entire; slightly revolute; ciliate.            Venation pattern: Pinnate; reticulate. Texture, upper and            lower surfaces: Pubescent; coriaceous, tough. Color:            Developing leaves, upper surface: Between 137A and 139A.            Developing leaves, lower surface: Close to 138A. Fully            expanded leaves, upper surface: Close to 139A; venation,            close to 138B. Fully expanded leaves, lower surface: Close            to 137C; venation, close to 151A. Petioles: Length: About 6            mm to 10.5 mm. Diameter: About 1 mm to 1.6 mm. Texture,            upper and lower surfaces: Pubescent. Color: Developing            leaves, upper surface: Close to N144D. Developing leaves,            lower surface: Close to N144D. Fully expanded leaves, upper            surface: Close to 138B. Fully expanded leaves, lower            surface: Close to 151A.-   Flower description:    -   -   Natural flowering season.—Spring, April to May, and then            remontant flowering during the summer and autumn, July to            October or until frost in USDA Hardiness Zone 6.        -   Flower appearance and arrangement.—Single flowers arranged            upwardly to outwardly in clusters at terminals and            sub-terminals; single whorl of five petals.        -   Flowering habit.—Freely flowering habit with usually about            one to three flower buds and three to six flowers per            cluster.        -   Flower longevity.—Flowers are durable and long-lasting;            depending on the temperature, flowers last about five to ten            days on the plant; flowers not persistent.        -   Fragrance.—None detected.        -   Flower diameter.—About 7 cm to 8 cm.        -   Flower depth.—About 4 cm to 4.5 cm.        -   Flower buds (before showing color).—Length: About 1 cm to            1.5 cm. Diameter: About 5 mm to 7 mm. Shape: Ovoid. Color:            Close to 137D.        -   Petals.—Length: About 3 cm to 3.5 cm. Width: About 3 cm to            3.5 cm. Shape: Broadly ovate to orbicular. Apex: Rotund;            undulate. Margin: Entire; undulate. Texture, upper and lower            surfaces: Smooth, glabrous; rugulose; waxy to velvety in            appearance. Color: When opening, upper surface: Close to            NN155C; central spots and speckles, close to 157D. When            opening, lower surface: Close to NN155C. Fully opened, upper            surface: Close to NN155C; spots and speckles, close to 157D;            color becoming closer to NN155C with development. Fully            opened, lower surface: Close to NN155C; color becoming            closer to NN155C with development.        -   Sepals.—Arrangement: Five in a single whorl, fused at the            base forming a campanulate to star-shaped corona. Length:            About 1.5 cm to 2 cm. Width: About 3.5 mm to 4 mm. Shape:            Lanceolate. Apex: Subulate. Base: Truncate. Margin: Entire;            slightly revolute; ciliate. Texture, upper and lower            surfaces: Densely pubescent. Color, upper and lower            surfaces: Close to 143C; central blotch and streaks, close            to 60D.        -   Peduncles.—Length: About 2 mm to 4 mm. Diameter: About 3 mm            to 4 mm. Angle: Mostly upright. Strength: Strong. Texture:            Pubescent. Color: Close to 145A; at maturity, close to 164A.        -   Pedicels.—Length: About 1.5 cm to 2 cm. Diameter: About 1.5            mm to 2 mm. Angle: Upright to outwardly. Strength: Strong.            Texture: Pubescent. Color: Close to 60D; towards the base,            close to 145B; becoming closer to N144A with development.        -   Reproductive organs.—Androecium: Quantity of stamens per            flower: About ten. Filament length: About 3.5 cm to 4.5 cm.            Filament color: Close to 67B. Anther shape: Porandrous with            four oblong, tubular to lunate-shaped pollen sacks basifixed            to the filament. Anther length: About 2.5 mm to 3 mm. Anther            color: Close to N186C. Pollen amount: Abundant. Pollen            color: Close to 158B. Gynoecium: Pistil length: About 4.5 cm            to 5 cm. Stigma shape: Round to flattened (capitate). Stigma            color: Close to N79B. Style length: About 4.4 cm to 5.9 cm.            Style color: Close to 61B. Ovary color: Close to 143B.        -   Fruits and seeds.—Fruit and seed development have not been            observed on plants of the new Azalea.-   Garden performance & temperature tolerance: Plants of the new Azalea    have been observed to be very tolerant to rain, wind and    temperatures ranging from about −25° C. to about 45° C.; and plants    of the new Azalea are suitable for USDA Hardiness Zones 6 to 9.-   Disease & pest resistance: Plants have not been observed to be    resistant to pathogens and pests common to Azalea plants.

It is claimed:
 1. A new and distinct cultivar of Azalea plant named‘RLH1-15P3’ as illustrated and described.